Calculate the annual depreciation expense for a piece of machinery purchased by Coca-Cola Company.

Item	Amount ($)
Cost of Machinery	400,000
Salvage Value	40,000
Useful Life	8 years
Depreciation Method	Straight-Line

Question:

Using the given data, calculate the annual depreciation expense for the machinery using the straight-line method. Show your calculations and explain the rationale behind using the straight-line method.